1. Field of the Invention
The invention relates to a straightening machine for metal plate and strip having an upper and a lower row of straightening rollers.
2. Description of the Prior Art
In a known straightening machine a set of upper straightening rollers are mounted in an upper frame, and the upper frame by means of driven spindles, is vertically displaceably connected to vertical bars of the machine frame. A set of lower straightening rollers are mounted in a lower frame which is pivotally mounted on both sides by means of arc-shaped surfaces on saddles guided between the vertical bars. By means of inclined surfaces the saddles are vertically displaceably supported in the frame on horizontally displaceable wedges. Each of the upper and lower straightening rollers is supported at their crowns by a plurality of back-up rollers. The back-up rollers arranged successively in the travelling direction, of a plurality of straightening rollers are always mounted as a set on bearing supports.
The bearing supports are individually supported on the upper frame and the lower frame, respectively, by means of adjustable wedges. The bending of the straightening rollers can be adjusted commonly by separate vertical displacement of each set of back-up rollers. By rectilinearly lifting and lowering, or by pivoting the lower frame, the lower straightening rollers may be moved together to a position which corresponds to the desired straightening gap.
The construction of these straightening machines with vertically adjustable upper and lower frame necessitates an expensive manner of construction with long bars. Thereby the stiffness of the machine is very low because of the length of the bars and their connection to the upper frame by means of spindles. It is a further disadvantage that in spite of complicated adjusting devices a separate adjustment of the straightening gap between a pair of straightening rollers on opposite sides of the gap is impossible and therefore the straightening gap cannot be varied in every desired manner.